Improvement in gages for carriage-axles



UNITED .i STATES PATENT Grinch,

HENRY HARPER, OIF BERLIN, WISCONSIN.

INIPRVMENTYIN GAG'ES FOR v(LAT-HdlAGE-AXLES.

Speeilieation ibriuingpart of Letters Patent No. 36,951. datedAbi-einher155i552 and useful inprovement in 'the manner ofgiving theproper pitch to the axle-arms or" carriages; and I do hereby declare the'following to be a true and exact description of my invention, whichwill be more i'ully understood by rel'erence to the accompanyingdrawings.'

It is very important that the bearing on the axlenrm should be the sameat both extremities of the axleloox. In order to secure this object, themiddle spoke in the lower halt'oi? the wheel should standperpendicularly when the carriage is on level ground. ofthe axleearms ismade horizontal,the "dish77 that is given to a wagon-wheel will inekethe spokes of the wheel incline outward from a perpendicular position,which would bring the bearing niore'on the point than on the shoulder ofthe axle-arm. 'lo ohviate this difr'liculty, the end ot' the axis of theaxle-arm is inclined downward, which brings the bottoni ot' the spokeinward.

The object oi my invention is to provide 'a simple and practical methodby which the end ot' this axis may be bent down wardjust enough to bringthe spokes perpendicular when they point downward. 'Iiiis could morereadily be donc il'gihe axleAai-in `were made of uniform sizethroughout; but for several reasons, some oi' which will be hereinafteralluded to, these aXle-arins are usually, it' not always, conslrnetedwith a considerable taper. One obt,rect ol this tapering l'orm is tosecure greater strength by the use ol' the saine weightI of inaterial,as the strain is greater near the shoulder than near the point ot't-heaxle-arni. v Another object is to bring the lower side ot' this laxle-arm as nearly horizontal as possible'. When this bearing-surlice oithe axle-arm is exactly horizontal, there will. be no tendency in thewheel to crowd either inward or outward, and it will therefore work withthe least possible amount ol' friction. This position is attained 'whenthe dish ot' the wheel is such that the spokes stand perpendicular tothetapering surl'ace of the axle arm, or, in other words, when the/:inglemade by the side of this tapering axle-armand its axis is equal to theoutward inclination oi' the spokes ot' the wheel which forms its dish.It, is not practicable lf the anis to secure this exact relation betweenthe dish of the wheel and the taper ot the axlearin,

`for, aside from the difficulty of establishingr it,

in the first/instance, the dish of the. wheel is generally increasedevery time the tire is ref set, which would preventthe continuance ofthis equality unless the taper ot' the axle-arm wereI changed wheneverthere was a change inthe dish the wheel. This exact equality is,however, rendered ot' less importance by the fact that a slight crowdingeither: inward or outward is not productivejof much inconvenience; and,besides, a. tendency in the wheel to 4crowd outward can readily becounteracted by incliuing thepoint of theaXle-arm slightly forward, anda tendency to crowd inward canin like manner be counteracted by bendingthe point ofthe axle-erin slightly back-werd.v

, I will now proceed to describe the contrivanees bywhich I secure theobject of my invention. I provide what I terni a beveh `Figure l, and ascale, Fig. 2. The rests a a aremade crescentshaped or coneaveron theirupper sides, so as to receive and hold the re-- spective axle-arms. Thedist-ance between these rests. is equal to the intended distance betweenthe tracks of the opposite wheels of the carriage. The points b b and ccare so arranged as to be in line with the/lowest portion oftherespective rests, so that when these bevels are Set at the proper pitchthe axle-arms may be placed thereon and readily brought to t-he santepitch. The scales at each end of this bevel are niade to have a motionaround the centers o o and between the clamps A A, and aremade fast atany given point by means of the clamp The scale, Fig. 2, has a brassrule, B, which revolves around the centeno and is held in any desiredposition by the clamp C and clamp-screw g. The iuimbcrs'on all thesescales represent inches from the center o.

lln order to tix the bevel at the proper pitch, I lay a straight-edgeacross the wheel on one side ot' the hub. Ithen measure down from thepoint ol' this straight-edge opposite the center of the hub to find thedistance of the spoke below that point. Suppose this to be two inches.This gives nie the depression or dish ot the wheel immediately outsideof the hub. lf, now, the distance from the outside of the hub to theouter circumference of the wheel is twentyfour inches, I then measuredownward on the scale helowey radial line .at its point. v ameters orradii will ytherefore he onehalf of seem l drawn thereon, and on theside marked in,? the distaneefof two inches upon the varc of a circlewhcl'iisat the distance of twenty-four inches 'frornthe center 0and setthe brass rule at that point, securing it with the clamp. v This givesme the angle of the dish ofthe Wheel.' Y

an inch. .OnthescalqFigt 2, and along the arc which isat eight inchesfrom the center o,

.lay oi ouehalf vinch 'from'the'point where thevbrass rule crosses thatarc. This'will lackronefl sixth of ad Aineh'of reaching the radial linefrom which the measurement commenced/fand which is coincident-With theupper'edge of the brass xii-ile, yas shown in the drawing'Fig.

2. Onlthe "scaley attached to one end of the` bevel, Figi., andalongthe'jarcwhichis at,u eight inches Tfrom' the center 9,1 now vlayedone-sixth of an inch below 'the iine,`. vvhic'h gives -a horizontalposition to the under-side of the axle-arm, and which is coincident withthe upper edge'iof the clamp A,as shown on the left-hand'end of the gurein the drawing. I no'rder to do this, vthat scale must have. been firstlpinclancp'edA and` raised upward" i arouudthe centero the requisitedistance and 'then reclamped,so as to bring the upper-edge of' the clampA exactly upon the point thus.

marked olf. This gives the proper pitch'to one end of the axle, and theother may be fixed in asimilarinanner.

instead of measuring by inches and fractions of inches,as above shown,abetter method Vwill be,by means of a pair of common divid ers,to measureo the actual distances repre e senting the dish of the wheel and thedifference of the radii of the two ends of the axlearni along the'respect-ive arcs of circles, and then to fix the, bevel accordingly,upon the sam Yprinciple'as is above set forth. f

As the dish of one wheel may very possibly be different from that of theother, the two' 'jends of the bevel may show different degreesof pitchfor the respective axlearms. `Having thus described my invention and theinode of its operation, what I claim as new, and

desire -to sec/ure by Letters Patent, is"

1. The method herein described of 'giving the proper pitch tocarriage-Wheels byfineans of the bevel, Fig. l, and thescale,r Fig.-2,sub-A 4stantially as set forth. l u 2. The'use of thehevel constructedas set forth, forthekr purpose of giving they proper pitch tocarrigefwheels, substantially in the manner above set forth. v

' -3. Scale, Figff, when used' inthe manner above setforth, for thepurpose ofgiving the proper pitchtoa carriagewheel.

HEENRYQHARPER.

Witnessesz.; Y

'- .f-TiioMAsLEhnLoN; Gr.y DE WITTELWOQD. 1

